Creating a parametric antique cap (for 3D Printing)

Hello,

I am trying to create a parametric antique cap so that I can change the thickness of the model without rebuilding everything. I'm pretty new to grasshopper and I was wondering if I can have some help.

Have a look at the image.

The object on the top left corner is what I modeled in Rhino/ the product I want to achieve. I have managed to model the cap and part of the leg. My difficulty is that I want to 

a. finish the leg so that the bottom is rounded. I have BREP'ed a negative to boolean. (might method, but OPEN to easier ways!). However I do not know how to move the boolean BREP into the right position. 

b. Then I want to multiple the individual legs by 3, and move it into the right position below the cap. them somehow boolean the 2 BREP's together for BAKING.

Any ways to achieve this? 

I built my own PRUSA i3 3D Printer and basically want to test this print at different thicknesses.

Thanks heaps.

Rui